Added user story 4 (Advanced filtering with smart contracts)

active/39-chat-moderation/README.md

@@ -36,10 +36,10 @@ The MVP provides users with basic moderation tools so that they can block users,
 
 ### User Stories 
 
-- [US 1: Blocking a user](https://github.com/status-im/ideas/blob/progress/39-init-reqeng/active/39-chat-moderation/user-stories/us-1-blocking-a-user.md)
-- [US 2: Reducing SPAM](https://github.com/status-im/ideas/blob/progress/39-init-reqeng/active/39-chat-moderation/user-stories/us-2-reducing-spam.md)
-- [US 3: Filter unwanted content](https://github.com/status-im/ideas/blob/progress/39-init-reqeng/active/39-chat-moderation/user-stories/us-3-filter-unwanted-content.md)
-- US 4: Advanced filtering with smart contracts
+- [US 1: Blocking a user](./user-stories/us-1-blocking-a-user.md)
+- [US 2: Reducing SPAM](./user-stories/us-2-reducing-spam.md)
+- [US 3: Filter unwanted content](./user-stories/us-3-filter-unwanted-content.md)
+- [US 4: Advanced filtering with smart contracts](./user-stories/us-4-advanced-filtering-with-smart-contracts.md)
 
 ### Requirements
 

active/39-chat-moderation/roles.md

@@ -5,5 +5,6 @@
 | Owner | Creator and owner of a chat. |
 | Moderator | User with rights to moderate a chat. |
 | User | Chat user without special rights. |
+| Power User | Chat user without special rights but ability to develop smart contracts. |
 | Contract Developer | Developer of contracts especially for chats. |
 | Contract Provider | Provider of contracts especially for chats. |

active/39-chat-moderation/user-stories/us-2-reducing-spam.md

@@ -16,9 +16,8 @@ Wish of *User A* to reduce SPAM in a public group chat.
 
 ## Pre-Condition
 
-A public chat room with traffic and *User A* as a user. *User A* decides that the
-quality of the feed doesn't match her quality requirements, the messages contain
-too much SPAM.
+A public chat room with traffic and *User A* as a user. Quality of the feed
+is too low for *User A*.
 
 ## Post-Condition
 

active/39-chat-moderation/user-stories/us-3-filter-unwanted-content.md

@@ -17,7 +17,7 @@ Feeds of *User A* contain a phrase the user doesn't want to see.
 
 ## Pre-Condition
 
-*User A* discovers phrases she dislikes and decides to ignore these messages.
+The disliked phrase is not inside the already added phrases of *User A*.
 
 ## Post-Condition
 

active/39-chat-moderation/user-stories/us-4-advanced-filtering-with-smart-contracts.md

@@ -0,0 +1,44 @@
+# User Story 4: Advanced Filtering with Smart Contracts
+
+## Description
+
+*User A* is a power user. *User A* configures her moderation rules to include
+the address of a smart contract that implements a standard rules interface.
+The smart contract will be called to evaluate new messages as they are received.
+
+## Trigger
+
+*User A* want non-standard actions to be performed for each received message.
+
+## Actors
+
+- *User A*
+
+## Pre-Condition
+
+The actions perfomed on arriving messages do not contain the wanted action.
+
+## Post-Condition
+
+After adding the address of a smart contract implementing the standard rule
+interface this contract will be called for each received message.
+
+## Flow
+
+- *User A* opens a (global|chat room) menu and selects the menu point
+  for adding smart contracts.
+- After entering the address of a smart contract and confirming the
+  adding the smart contract will be checked for implementing the standard
+  rule interface.
+- In case of a valid implementation the smart contract will be added.
+
+## Remarks
+
+- Question: Is the only one global list for all messages or also individual
+  lists per chat room?
+- Question: Only one contract (global or per chat room) or multiple ones?
+- Question: In case of multiple contracts, can the order of their execution
+  be defined?
+- Question: Can contracts filter messages or send new messages? And the latter
+  to *User A* or also to other users?
+- Todo: Add user stories for the manipulation of the contract set.